Replacing Fuel Pump Covers with Aftermarket Ones

Smashing the accelerator while at speed this winter, I had a whole bank of misfires (4 of the 6 cylinders on the right hand side). Having identified the dreaded black crud in my fuel filter, I decided this winter I should pop the fuel pumps out and take a look. As many of you have discovered, ethanol had really wreaked havoc on those puppies, completely disintegrating one of the pump gaskets, and doing a fair number on the other, depositing a healthy dose of black crap into the tank. Indeed, the right hand fuel pump intake on the actual pump was largely obscured with black gasket material. So, seems I found the problem.

There are several real good posts on these fuel pumps, and I am going to attempt to stay away from their discussion, and cover some new items I don’t see in the forums. The big thing is I am going to cover the installation of an aftermarket fuel pump cover I chose to put on (if you have it all apart, might a well do a bit of housekeeping). If you are searching for fuel pump removal/gasket replacement, read this thread from Strongx first:

https://www.ferrarichat.com/forum/threads/another-case-of-dissolving-rubber-in-the-550-gas-tank.379853/

Also, this thread from Robbe was helpful:

https://www.ferrarichat.com/forum/threads/small-tutorial-on-repairing-the-550-fuel-pump.631056/

Before we begin, here are some parts you will want to order ahead of time. Posting links to help; I am not affiliated with any of these; but locating some of these was a real task. I used my dealership for some of these parts, but as Ricambi is a sponsor, figured best to post their links.

(2) fuel pump gaskets: https://www.ricambiamerica.com/170511-gasket.html
(2) fuel pump anti-vibration pads (mine were completely gone; yours are probably gone as well): https://www.ricambiamerica.com/126807-plate.html
(2) 173890R fuel pump covers (these are $700/each, but I am keeping this Ferrari for ever, so made the leap). I did not buy mine from here, but this is one source. Search for 173890R for some options. https://www.ferraripartsexchange.com/products/173890r
(4) small o-rings for feed tubes: https://www.ricambiamerica.com/127816-o-ring.html
(1) package of post-to-stud connectors (you need 4, but good luck finding just 4)
https://www.amazon.com/gp/product/B01MR3BILR/
(2) M5-0.8x50mm socket head cap screws, stainless
(2) M6-1x50mm socket head cap screws, stainless (I bought both sets of screws from Amazon, but some of you gearheads may have them in stock)
(1) stainless metric locknut assortment M3-M10, because you can never have enough of these. https://www.amazon.com/gp/product/B074PJV3N1/
(2) 240mm submersible corrugated fuel hose with 10mm on ends. You can get these from a couple of sources, but I liked this small vendor the best (and he was fast): http://apeusa.com/html/kits.html
(1) segment of submersible fuel line (for the return connection; must be SAE-30R10): https://www.amazon.com/gp/product/B001R5XSGU
(4) Stainless Oetiker clamps (get a set of these, you will use them elsewhere on a 550): https://www.amazon.com/Leberna-Stainless-Stepless-Automotive-Assortment/dp/B07QLGR7T5/


Now if you have gotten this far, you will thank me for this part (it took me forever to find this puppy!!!!). In my writeup I will explain my logic for these, which you may or may not agree with:
(2) 2-way metripack 280 sealed pigtails https://www.bmotorsports.com/shop/product_info.php/products_id/1596


Order these parts before you start. I know the gaskets are expensive, but if you don’t have to replace them now, you will later.

Now, IMPORTANT CAVEAT: I ain’t a pro. I am a shadetree mechanic at best. If in doubt, ask the crew here, because there are some great minds lurking in these forums, or take it to your trusted mechanic. Also, read the comments following this post, as I am sure I will be corrected on some things!

I am not going to go through the whole process, but will add some modifications/enhancements to the process posted by strongx above.

First “enhancement.” To drain the tank, I use the FatBillyBob method to short one fuel pump relay and drain the fuel through the fuel rail on that side. To do this, get a Schraeder valve tool (cheap, amazon or Advance Auto), and remove the valve on the appropriate fuel rail. Before doing this, get something under that opening, and know it can have a little pressure if you operated the car that day. Once off, I attach 4’ of ¼” fuel hose to it, so that the fuel routes out of the engine bay and into an awaiting gas can. The relay is easy to find, in the fuse box in front of the passenger footwell, on the left hand side. Master power has to be on, but key does not need to be there. Works like a charm (thank you, FatBillyBob! Someday I will meet you in person and buy you a drink!).
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I don’t have welding tools, so my tool to remove the fuel pump nut was home made with some flat bar I had, cut down to around 140mm, with two 6mm holes drilled into it spaced 116mm apart. I used 6mm x 70mm bolts, with the heads dremeled off like Strongx suggested. To hold it in place, however, I simply used two nuts, one on each side of the flat bar, thus didn’t have to tap it. This stays in my ever growing tool box of custom fabricated fancy Ferrari tools! Before turning these, put a cookie sheet under the pump you are working on, as no matter how good you are, gas will come out of something.

Getting those pumps out sucks, but is doable. To pull the pump covers, I replaced the holder bar at bottom and pulled away at it. Those came off easy, but the hard part for me was getting the pump housing out. One hint from Robbe’s post on this that was helpful was to remove the bolt connecting the top bar to the pump holder. It does allow you greater wiggle freedom. A thin screwdriver was needed to motivate the plastic into the exit hole. Make sure the return tube, which goes on the outside of the pump housing is in its little groove, or you will have to fight to squeeze it through.

Once out, clean out the loads of dissolved rubber all over the bottom of your tank. It’s bad.

Remove the return tube from the bottom of the housing; it comes out fairly easily with a little motivation using a flathead screwdriver on the tip. Remove the steel retaining frame by pushing the little tabs in on the side. My fuel pumps were free floating in there, but take the fuel pump and filter basket out of the pump housing. The filter basket and gasket housing is retained by four simple tabs, and a good tug gets the housing out. Once out, there are a few screws on the circumference of the filter basket that separate it from the retainer for the gasket. And start cleaning all that degraded nasty gasket. After the tank is cleaned up, I covered my holes with saran-wrap held in place by the retaining ring, knowing I was going to have to work a bit on those pumps. I recommend this, because the prospect of critters or contaminants getting in the tank is not cool.
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Now for the new stuff. I bought my aftermarket fuel pump covers from my dealer who had an extra set around from a job that apparently didn’t get approved after they bought the parts. These are nice, but they have some differences and you have to rebuild stuff here. I am very interested in keeping the original parts of the car intact, so I did not want to cut the wires from their connectors and splice them into the provided barrel connectors. Cutting the wires and simply attaching them to the barrel connectors would be easier. But, Ferrari.

Take M6 and M5 bolts out of assembly. Don’t lose the four little gaskets. You will replace these bolts with the longer bolts listed above (this is to hold the exterior connector). On the inside of the covers, I used stud mounted male quick connect tabs. For the M6 stud, I had to file a little of the center hole out, but still had plenty of meat. Put the connect tabs on the longer replacement bolts, and place the large washer on top of that. Then, place the small gasket in its place, and screw each replacement bolt in. I carefully noted which color wire goes to which connector, as I did not want electricity going the wrong way to the pumps. To pull the factory fuel pump connectors out of their housing, a terminal removal kit is very valuable. If you have such kit, place a two-pin extractor on top to hold down the retaining tab while you place a small flathead screwdriver between the connector and the plastic and turn it slightly to allow the wire to come out the back (there is a 1mm stub towards the front, bottom of each connector, holding it in).
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For the outside connector, I wanted to keep it as it is from the factory, with a metripack sealed connector. You could just cut the factory connector, and simply strip the wires and connect, but there are some issues with that, including difficulty in removing this in the future. So, I went with a proper female connector. To do this, I had to find a way to affix it to the pump cover. What I came up with is to replace the two socket head cap screws in the covers with ones that were 5mm longer. This allowed me to create a sandwich with nuts to hold the female metripack connector in there. First, put the small gasket in, the large washer on, and the crush washer on, followed by the provided nut. Tighten down, keeping the tabs on the inside correctly aligned. I cut the pigtails to a reasonable short length, attached them to the barrel post connectors, and also used some heatshrink wire wrap to cover up the wire work (not needed, just a stupid old habit I have). Next, cut some small notches in the side of the metripack to slide the connector between the two head cap screws. Put these notches in deep enough so the metripack does not hit the tank when installed, and not so far as to interrupt the feed hoses. Then, put a metric locknut on top of each post, tightening the metripack connector down. Remember, the bolts conduct electricity, so don’t retain the metripack with a conductive material. I kinda like what this looked like when finished (brag brag brag), and this arrangement feels pretty solid.
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The fun part is the old hoses. I chose to replace the feed hose, and the first segment of the return hose. In all my research, I couldn’t find anyone who had a way to get those off without sacrificing them, so be sure you have the replacement hoses in hand before you start this; they don’t seem to be at local car parts places. To remove them, you have to cut a slit out of them at the barbs. It took me quite some work to find the right corrugated fuel hose, but the measurements above do work (~240mm, with 10mm openings on both sides). Important note, my fuel barb fittings were 10mm. I have noticed pictures of this aftermarket cover with what appears to be 8mm fitting barbs. They do make the corrugated tube in 10mm/8mm sizes as well. For the return line, I used a small section of submersible fuel line hose to go from barb to one-way-valve. Do not use normal fuel line in the tank, or you will be doing this again. You need to use SAE 30R10 for this small section. You can opt for an 8mm fuel barb on the return line feed from the pump cover, as it will make fitment easier. Ask me how I know…

When reassembling, the filter/pump sub-assembly has a little wave that lines up with the return hose divot in the outer assembly. I don’t know if aligning that is critical, but why take chances. Also, the gasket has a small hole for the breather snorkel, and the gasket housing has a small notch to accommodate the snorkel. Be sure to line that up when you put it together, or you will need to go back a few steps to do so. The snorkel seems to be an oft-forgotten part. I used a new ziptie to hold the corrugated fuel tube and pump power wires to the top support bracket. I did fiddle with the routings of this, as the fuel tube seems long, but so did the stock Ferrari one. Also, remember the anti-vibration gaskets on bottom. I have no idea how the hell they are supposed to stay on, and it took some hand-in-tank corrections to refit them.

Before reattaching the external fuel fittings (outside tank), replace those small o-ring gaskets. 20 years has not been kind to gaskets. On one of my replacement fuel pump covers, the return hose fitting did not have a proper bevel, and it ate a couple of o-ring gaskets before I spotted the issue. I used 400-grit sandpaper on my finger and was able to put a small bevel in there that worked perfectly. When fitting the lines, I used Mobile 1 oil to lube the o-rings, which is also helpful. One final gotchya on the fuel fittings, the red return fitting was too long on my pump covers, and I had to trim some of the plastic back. I was not happy with this, but saw no other alternative. The threaded base of the internal barb fittings only gave 7.5mm of clearance for the nipple of the fuel fitting. Once trimmed to 7.5mm, the seals were good, and the system held fuel. This is when it is invaluable to have a wife who drives manual Ferraris, because she can fire it up while you watch for leaks.
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Rinse, wash, repeat for pump #2.



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